The flame on a water heater typically stays on during heating cycles but may turn off when the desired temperature is reached, ensuring safety and efficiency.
Many homeowners wonder whether their water heater’s flame should stay on constantly. The answer is simple: your pilot light stays lit continuously, but the main burner flame only ignites when hot water is needed. Understanding this distinction helps troubleshoot issues and maintain your system efficiently.
How a Water Heater Flame Works
Gas water heaters use a two-stage flame system:
- Pilot light: A small, constant flame that remains lit 24/7
- Main burner: A larger flame that activates only during heating cycles
The Pilot Light’s Crucial Role
The pilot light serves as an ignition source for the main burner. When your thermostat detects cold water, it signals the gas valve to release fuel to the main burner. The pilot light then ignites this gas, creating the large flame that heats your water.
Modern water heaters may use electronic ignition systems instead of standing pilot lights, but the principle remains similar. The ignition source activates only when needed, improving energy efficiency.
Common Flame-Related Issues
Pilot Light Problems
If your pilot light won’t stay lit, you might experience:
- No hot water
- Inconsistent water temperature
- Higher energy bills (if using electric backup)
Common causes include a faulty thermostat, dirty thermocouple, or gas supply issues. For persistent problems, consider replacing components like the pilot assembly.
Main Burner Issues
When the main burner malfunctions, you might notice:
- Short cycling (frequent on/off cycles)
- Yellow or orange flames (should be blue)
- Sooting around the burner
These often indicate improper combustion, which requires professional attention. According to Energy.gov, improper burner operation can reduce efficiency by 10-25%.
Flame Color: What It Tells You
| Flame Color | Meaning | Action Required |
|---|---|---|
| Blue | Normal operation | None |
| Yellow | Incomplete combustion | Clean burner or adjust air mixture |
| Orange | Dust in burner | Clean burner assembly |
| Flickering | Draft issues | Check venting |
Maintenance Tips for Optimal Flame Operation
Annual Inspection
The American Home Shield recommends these annual checks:
- Inspect flame color and pattern
- Clean burner and combustion chamber
- Check gas connections for leaks
- Verify proper venting
When to Call a Professional
Seek professional help for:
- Persistent pilot light outages
- Gas odors
- Visible soot around the unit
- Unusual noises during operation
Energy Efficiency Considerations
While the pilot light does consume some gas continuously, modern units use about 600-900 BTUs per hour – equivalent to a couple of stovetop burners on low. Newer electronic ignition models eliminate this constant energy use, saving approximately $10-20 annually according to Department of Energy estimates.
For maximum efficiency, consider upgrading to a tankless system if your household meets the usage patterns these units serve best. These only activate when water flows, eliminating standby losses entirely.
